baetlett



(No Model.) 2 Sheets-Sheet 1.

0. BARTLETT.

' CIRCUIT CLOSER.

" No 281,608. Patented Ju1y 17, 1883 VWTNEEEEE: JNVENTUH: I

I .I IL L I G/zarZ esBartZ ett (-No Model.) I '2 Sheet-Sheet 2.

' U. BARTLETT;

CIRCUIT CLOSER. N0'.'281,6'03. Patented July 17', 1883,,

UNITED STATES PATE T OFFICE.

CHARLES BARTLETT, or PROVIDENCE, ASSIGNOB OF ONE-HALF TO FRANK J.srnncnn, or PAWTUGKET, nnonn ISLAND.

CIRCUIT-CLOSER.

SPECIFICATION forming part of Letters Patent No. 281,603, dated July 17,1883,

' Application filed January 22, 1883. (No model.)

thus shut off the whole line in which their keys are located, has been asource of great annoyance. This invention has referenceto a device forovercoming that difficulty.

The invention consists in the provision of an independent loopconnecting the line-wire or any two points on opposite sides of the key,

and of an automatic circuit-closer, which keeps the loop-line alwaysclosed until it is purposely thrown open, as hereinafter set forth.

Figure 1 is a view of a disk provided with a button and two line-wires,constructed so that the circuit is closed until the button is depressed.Fig. 2 is a reverse view of the same, showing the two metalconnecting-plates and the spring for operating the button. Fig. 3 is asectional view of the device, showing the button forced out by a springand the two plates in contact. Fig. 4 is a sectional view of the device,showing the button depressed and the plates separated. Fig, 5 is a viewof the line-wires and a connection around the telegraph or telephoneinstrument by means of the loop.

A A are the line-wires.

B is the loop, composed of wires a a and connections. These wires a areconnected with the main line at each side of the instrument 0, which maybe either a telegraph-key or a telephone-instrument.

d is a button, which serves as a .circuitb and 0, one lying underneaththe other, and

held in contact by spring 0 until thrown apart to break circuit by theoperation of button (I. Itwill be seen that the direct course of thecurrent will be through the instrument 0, and

that when this is closed, and the loop also is closed, the current maypass by either line. Should the instrument 0 be left open, however, theloop B, which is normally closed, will still complete the circuit, and amessage would pass along the line A A through said loop. When theoperator sits down to transmit a message by means of key 0, he breaksthe circuit in loop-line B by pressing in the button d with his foot orknee, or in other convenient manner. When he steps away from theinstrument, he removes the pressure from button d, and although theinstrument 0 be left open, the circuit along themain line and loop iscomplete by the automatic closing of the circuit-closer in the loop.

It is obvious that various devices for opera telegraph or telephoneinstrument, of a loop connected with the line at each side of theinstrument and a springpressed key in said loop to maintain theloop-line normally closed, substantially as stated.

3. The combination of the line-wire, the illstrument, the loop -wires'connected as described, the switch-plates b c, and the spring e, withthe button d, all being relativelylarranged, substantially as stated.

' CHARLES BARTLETT.

Witnesses:

M. F. BLIGH,

J. A. MILLER, Jr.

